The present invention relates to etching a layer of non volatile materials through a mask during the production of a semiconductor device. More specifically, the present invention relates to etch a metal magnetic tunnel junctions (MTJ) stack.
During semiconductor wafer processing, features may be etched through a metal containing layer. In the formation of magnetic random access memories (MRAM) or resistive random-access memory (RRAM) devices, a plurality of thin metal layers or films may be sequentially etched. For MRAM a plurality of thin metal layers may be used to form magnetic tunnel junction stacks.